1. Field of the Invention
The present invention relates to a cold preserving container or refrigerator which has means for cold accumulation.
2. Description of the Prior Art
Generally, a cold preserving container or refrigerator is constructed of an inner box defining a heat insulating chamber, an outer box covering the inner box and a heat insulating material provided between the inner box and the outer box.
As the means for actively cooling the inside of the heat insulating chamber or maintaining the cold air in the heat insulating chamber, the cooling mechanism assembled into the cold preserving container or the cold accumulation component including a cold regenerative material is known. The cooling mechanism comprises, for example, an evaporating tube through which an evaporated cooling medium circulates, a compressor, a condenser and an expansion valve. The evaporating tube can cool the inside of the heat insulating chamber, and can also cool the cold accumulation component. The cold accumulation component is usually placed between objects contained in the heat insulating chamber or at the upper position of the inside space of the chamber. Thus, the cold accumulation component is cooled via the cold air in the chamber, and the cold obtained by the cooling is accumulated in the component.
In such a cooling and accumulating mechanism, however, since the heat exchange is performed between the cold accumulation component and the cold air in the heat insulating chamber, the heat exchange is not very effective, and it takes a relatively long time to cool the component to the desired temperature. Therefore, it is difficult to quickly and adequately cool the cold accumulation component. On the other hand, when the component is adequately cooled, the temperature of the air in the heat insulating chamber is too low.
Moreover, since the cold accumulation component is placed in the heat insulating chamber, the size and capacity of the component is often thereby limited. Also, the time during which the contained objects can be maintained at a sufficiently low temperature is limited, for example, to only one to three hours.